The present invention relates to an NC (Numerical Control) system having a display unit such as a CRT (Cathode-Ray Tube) and which is operable on an interactive basis.
FIG. 1 of the accompanying drawings illustrates a control panel of a conventional NC system having a CRT, and FIG. 2 shows sections of the control panel in greater detail.
The control panel has a CRT 1, and a display-image selecting key group 2 for selecting display images on the CRT 1. The key group 2 includes a plurality of keys 21 through 28, a data key group (numeric keyboard) 3 for entering data, an address key group 4 composed of alphabetical keys for distinguishing data contents, a data editing key group 5 composed of a plurality of keys 51 through 58 used for editing data entered on the CRT 1, and a mode selecting key group 6 composed of a plurality of keys 61 through 68 used for selecting operating modes of the NC system and a machine being controlled thereby. These various keys are associated with respective switches.
The procedure to be followed by an operator in entering a machining program through the control panel will be described with reference to the flowchart of FIG. 3.
First, the operator switches on a power supply in a step (a). Then, the operator decides what to do next dependent on the work to be done by a machining program to be entered in a step (b). In the illustrated example, a program generation switch 66 in the mode selecting key group 6 is depressed in a step (c) for selecting an operating mode in entering the machining program. A program switch 23 in the display-image selecting key group 2 is depressed in a step (e) for selecting a display image on the CRT 1, and an image for generating the machining program is displayed on the CRT 1 in a step (f). The operator then decides what to do next in step (g): in this example he depresses a "p" switch which is pre-set in the address key group 4 and a "1" switch, a "6" switch, and a setting switch which are coded in the data key group 3 for setting a program number in a step (h). The operator also depresses a "G" switch in the address key group 4 and an " O" switch and a "setting" switch in the data key group 3 for setting a preparatory function in a step (j).
Then, the operator decides what to do next in a step (k), and here depresses an X-switch in the address key group 4 and a "2" switch, a "4" switch, the "6" switch, a "." switch, a "3" switch, and the "setting" switch in a step (l) to establish that the X coordinate of a target positioning point is "246.3". Likewise, in deciding what to do next in a step (m), the operator depresses a "Z" switch in the address key group 4 and the "6" switch, the "2" switch, the "3" switch, the "." switch, a "5" switch, and the "6" switch in the data key group 3 in a step (n) to establish that the Z coordinate of the target positioning point is "623.56". Thereafter, the operator depresses an "M" switch in the address key group 4 and the "3" switch and the "setting" switch in the data key group 3 in a step (p) for setting auxiliary functions such as setting of a spindle and starting and stopping of a coolant, for example. All necessary auxiliary functions are set in a step (q) by depressing the "M" switch in the address key group 4 and the numerical keys in the data key group dependent on the auxiliary functions to be set.
Subsequently, when the operator decides what to do next in a step (r), he depresses a "G" switch in the address key group 4 and the "1" switch and the "setting" switch in the data key group 3 for setting a preparatory function in a step (s). Then, the operator repeats the decision and setting operations while viewing a process sheet which has been prepared in advance, and sets auxiliary functions as necessary to thereby complete the generation of the program in a step (x).
With the prior NC system thus arranged, the operator has to make decisions many times and operate on the control panel highly frequently. This is disadvantageous in that the procedure is complex and not efficient. The control panel is composed of a large number of parts, and hence requires many wiring and assembly steps in its manufacture and takes up a large space. As more and more functions are added to the NC system, the above problems become more and more severe.